A multiple user multiple input multiple output (MU-MIMO) technology, as one of core technologies of wireless communication standards, such as the 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE) and Long Term Evolution Advanced (LTE-A), can improve spectral efficiency and a system capacity of a wireless communications system. A pilot signal, as a constituent part of the MU-MIMO technology, is used to identify different antennas, and guide a user to perform channel estimation, so that the user can receive data correctly. In addition, a pilot signal occupies a transmission resource. For an entire communications system, excessively high pilot overheads cause congestion in the communications system. As a result, useful data cannot be transmitted in time.
In the prior art, a spatial multiplexing technology is used to reduce pilot overheads, where users that are paired with each other use a same pilot, and orthogonalization of a pilot signal of the paired users is implemented at a transmit end, so that each user receives a corresponding pilot signal.
In a process for implementing reduction of the pilot signal overheads in the foregoing, the inventor finds that interference exists between multiple paired users that use a common pilot, and strength of an orthogonal pilot signal received by a user to whom interference is larger is weaker. In this way, although pilot overheads are reduced, accuracy of user channel estimation is affected, and therefore, correct data reception of a user is affected.